| TERMS | DESCRIPTION |
| Tag | is being used for the old term EID (Entity IDentifier) and for the new term object identifier. A Tag identifies an object in the NX database. The objects are not limited to geometrical objects, but can include parts, instances, and occurrences. |
| Piece Part | This is the lowest level part in an assembly; it contains geometry and features that represent the physical object, but no components. |
| Occurence | When several parts are brought together into an assembly, the parts and their objects are not copied into the assembly part. Rather, the parts are loaded into memory, and part occurrences of those parts are put into the assembly part. |
| Object Occurrence | For each object in the piece part, an object occurrence of that object is made in the assembly part. |
| Instance | This is the term used to indicate the placement of a component part within an assembly part. For each Instance, a Part Occurrence is displayed in the assembly part. |
| Multi-level | Assemblies can be multi-leveled. For example, an automobile can consist of the body and two instances of an axle assembly part, which itself consists of an axle and two instances of a wheel assembly part, which itself consists of .... etc. In these cases, each Instance can have more than one associated Part Occurrence. |
| Component Part | This is the usage of a part within an assembly, at a particular location
and orientation. A component may be a sub-assembly consisting of other,
lower-level components. Each component in an assembly contains only a link
to its master geometry. When you modify the geometry of one component,
all other components in the session using the same master update automatically
to reflect the change.
Old (V9) style components are stored in the Database as Type 63, Subtype 0. New (V10) style components are listed as Type 63, Subtype 1. |
| Prototype | This is the master geometry to which an occurrence is linked. In the case of a part occurrence, it is the piece part containing that master geometry. |
| Reference Set | This is a named collection of geometry from an NX part that may be used to simplify the representation of the component part in higher level, large, complex assemblies. Whenever the name of a reference set is passed in to a routine, if the string is NULL or blank, the whole part is used. If the string "Empty" is used, the empty reference set is used. |
| Displayed Part | This is the part that is being viewed in the graphics window. It can either be a piece part or an assembly. The displayed part must be fully loaded. A partially loaded part can be made the displayed part by opening it. |
| Work Part | This is the part whose geometry or assembly structure is being modified. The Work Part can be the same as the Displayed Part or any component of the Displayed Part if it is an assembly. The work part may be partially loaded, but must be a member of the assembly which is the displayed part. Only objects of the work part may be edited. Object occurrences can not be edited, but they may be queried to find their data. |